Server 2012 Activation Error 0x8007007B

I recently noticed that I had one server that refused to activate.  There were several of these begging for activation before I got Key Management Server (KMS) up and running and I thought they had all activated. Apparently, I overlooked one.  I logged into a rarely used box and there it was, requesting activation.  Ok, simple enough, I didn't know why it hadn't activated on it's on, but that was ok, I'd click the box to activate it.  Not so fast, I clicked the box, waited for it to finish and then I got hit with a "0x8007007B Windows couldn't be activated" error message like this one.

How friendly, at least it had an error code.  So I started my search of what causes this error.  I investigated some of the causes others had posted and didn't have any luck.  Then I found this Microsoft knowledge base article.  Method #3 is what pointed me in the right direction.  I tried the mention command

nslookup -type=all _vlmcs._tcp>kms.txt

and got this "Non-existent domain" error message.

I don't think that's supposed to happen.  I try this command on another server and it generates a nice pretty txt file similar to what's shown in the kb article.  This means we've uncovered another sympton.  Time to do some more digging and to figure out what can cause this error.

It turns out what was happening is that the DNS suffix (the part after the host name) wasn't getting added correctly to DNS queries.  What this means is when it tries to lookup these records that it is failing because it doesn't know the domain name, hence the "Non-existent domain".

Here's an article that I found about DNS suffixes.  It mentions this handy powershell command to check your settings.

Get-DnsClientGlobalSetting

Here's what my settings looked like.

This might be part of my problem.  Off to the network adapter configuration we go.  I check the DNS settings and the DNS suffix for the connection appears to be correct.  For whatever reason the server is just refusing to use it.   Luckily, there's a handy "Append these DNS suffixes" section right above that. I added the correct DNS suffix right there. It now looks similar to this screen.

After click OK half a dozen times I was ready to try to activate Windows again. Success.... It worked that time.